Artificial filament capable of being dyed with wool and chrome dyestuffs



Patented Mar. 26, 1940 UNITED STATES PATENT OFFICE ARTIFICIAL FILAMENT CAPABLE OF BEING DYED- WITH WOO STUFFS L AND CHROME DYE- G. Farbenindustrie Aktiengesellschaft,

Frankiort-on-the-Main, Germany No Drawing.

Application June 2, 1939, Serial No. 277,018. In Germany June 4, 1938 4 Claims.

Our present invention relates to artificial filaments capable of being dyed with wool and chrome dyestuffs.

It has been proposed to incorporate with spinning solutions for making artificial threads from viscose substances containing amideor imidegroups, for example cyanamide, and then to spin the solution in a spinning bath containing formaldehyde. The viscose which is prepared in this 10. way can be stored without change for a longer period than can viscose which has not received the addition. The filaments made from the viscose have a normal dyeing capacity similar to that of the viscose without an addition.

It is an object of the invention to provide threads and similar textile materials such as bristles, foils, ribbons, etc., which consist of cellulose hydrate or cellulose esters or ethers, but which possess a similar capacity as wool to be dyed by acid dyes.

Further objects of our invention will appear from the specification following hereinafter.

This invention is based on the observation that resinous condensation products obtainable by the reaction between cyanamide and acetaldehyde or any higher aldehyde but not formaldehyde are suitable for improving the dyeing capacity of the filaments produced from spinning solutions. If one of these products in solution or fine dispersion is added to the spinning solution, it remains in the thread produced from the solution and imparts to the thread a capacity for being dyed well and fast by means of acid wool and chrome dyestuffs. By the correct proportioning of the condensation product from cyanamide and aldehyde, fibers are produced which, in respect of their capacity for being dyed with acid wool dyestuffs, are not inferior to wool fibers. Depending on the properties of the condensation product, processes for spinning the solution are those in which no acid precipitating bath is used, for instance that described in the U. S. Patent No. 2,082,814, as well as the acid spinning processes.

The condensation p oducts may be made in a manner similar to tha in which the condensation products from cyanimide and formaldehyde are made (U. S. Patents Nos. 1,791,433 and 1,791,434). The condensation products from cyanamide and acetaldehyde are in part soluble in alcohol and in part insoluble. They are introduced either in solution, for example in alcohol, or undissolved in finely subdivided condition into the spinning solution in the course of its manufacture. Compounds which are not of themselves soluble in alcohol may, if desired, be made soluble in alcohol by dissolution in an acid and subsequent precipitation by alkali. The reprecipitated product is especially useful as an addition to spinning solutions. Both the products which are soluble in alcohol as well as those which are insoluble are preferably spun into a neutral spinning bath and afterwards dyed in a neutral bath with acid dyestuffs, since they are soluble in acids.

The condensation products from cyanamide and aliphatic aldehydes of higher molecular weight surpass those formed from acetaldehyde. The product of the reaction of cyanamide with for instance isohexylaldehyde is a resinous feebly yellow substance which is soluble in alcohol but practically insoluble in water, alkalis and acids. In consequence it may be used in the xanthate spinning process and in the acid spinning process and yields a fibrous material which dyes like wool in an acid bath. It is important to attain a thorough emulsification of the body in the viscose. This can advantageously be achieved with the aid of a good emulsifying and dispersing agent, for example with the aid of Turkey red oil, Praestabitol" registered trade-mark (Textilhilfsmitteltabellen, by J. Hetzer, Berlin 1933, pages 143-145), Emulphor registered trade-mark (Hetzer, l. c., page 49) and others. Especially suitable, however, are additions like esters of high boiling point, for instance triphenyl and tricresyl phosphates which are known as softening agents (Jordan, Chemische Technologie der Liisungsmittel, 1932, pages 288 and 289) Such additions affect favorably the ailinity of the dyes as well as the uniformity with which they are adsorbed.

The following examples illustrate the invention, the ratio between parts by volume and parts by weight being that between the liter and the kilo:

1. To 1 liters of a viscose containing 8 per cent of cellulose and 6.5 per cent of alkali are added 20 grams of the product from cyanamide and acetaldehyde redissolved by hydrochloric acid. By spinning as prescribed in U. 8. Patent No. 2,082,814, followed by a thermal decomposition, a fiber is obtained containing 1.8 per cent of nitrogen.

2. 18 parts by weight of isohexylaldehydecyanamide-condensate are dissolved in 65 parts by volume of cyclohexanol and the solution is emulsified in 2000 parts by volume of a viscose containing 8 per cent of cellulose and 6.5 per cent of alkali. This viscose is spun in a Miiller bath and yields a fiber having about 1.6 per cent of nitrogen.

3. 18 parts by weight of isohexylaldehydecyanamide-condensate are dissolved in 60 parts by volume of cyclohexanol and there are added 20 volumes of triphenyl phosphate or tricresyl phosphate. The material is spun in an acid bath as described in Example 2.

We claim:

1. Artificial cellulosic filaments having an increased aflinity for acid dyes and containing finely dispersed within the body of the filaments the condensation product of cyanamide with an aliphatic aldehyde having at least two carbon atoms.

2. Artificial cellulosic filaments having an increased afiinity for acid dyes and containing finely dispersed within the body of the filaments the alkaliand acid-resistant condensation product 0! cyanamide with an aliphatic aldehyde havinz more than five carbon atoms.

3. Artificial cellulosic filaments having an increased afiinity for acid dyes and containing finely 4. Artificial cellulosic filaments having an in creased aflinity for acid dyes and containing finely dispersed within the body of the filaments the condensation product of cyanamide with isohexyl aldehyde.

- ERICH GRAUMANN.

GUSTAV-ADOLF scrmb'ma. 

